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Interlude E

New Data Found to Help Understand Evolution, Extinction Impact

Science, 24 Dec. 2004

Researchers studying the effects of predator extinction on biological communities analyzed ancient extinction events and carried out controlled laboratory experiments by examining where predator snails have drilled holes on clam shells to extract meat.

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Active Reading Questions

  1. In order to effectively use the data they are collecting, which of the following inferences are the scientists featured in the article making?
    a) Hole-drilling snail behavior was similar in the ancient and modern species.
    b) The location of a drilled hole in a shell correlated well with predator numbers.
    c) Extinction has an effect on predator abundance.
    d) All of the above.
  2. Evolution at the species level is referred to as _____________.
    a) microevolution
    b) macroevolution
    c) speciation
    d) explosion
  3. The extinction event discussed in the article occurred about 1.8 million years ago during the Pliocene; this is not considered one of the five mass extinctions discussed in your text. Use your book to list the five mass extinctions along with when they occurred.
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